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<pre><span class="sourceLineNo">001</span><a name="line.1"></a>
<span class="sourceLineNo">002</span>/*<a name="line.2"></a>
<span class="sourceLineNo">003</span> * Copyright (C) 2011 Archie L. Cobbs. All rights reserved.<a name="line.3"></a>
<span class="sourceLineNo">004</span> *<a name="line.4"></a>
<span class="sourceLineNo">005</span> * $Id: VersionComparator.html 689 2013-06-28 19:22:16Z archie.cobbs $<a name="line.5"></a>
<span class="sourceLineNo">006</span> */<a name="line.6"></a>
<span class="sourceLineNo">007</span><a name="line.7"></a>
<span class="sourceLineNo">008</span>package org.dellroad.stuff.string;<a name="line.8"></a>
<span class="sourceLineNo">009</span><a name="line.9"></a>
<span class="sourceLineNo">010</span>import java.util.ArrayList;<a name="line.10"></a>
<span class="sourceLineNo">011</span>import java.util.Comparator;<a name="line.11"></a>
<span class="sourceLineNo">012</span>import java.util.List;<a name="line.12"></a>
<span class="sourceLineNo">013</span>import java.util.regex.Matcher;<a name="line.13"></a>
<span class="sourceLineNo">014</span>import java.util.regex.Pattern;<a name="line.14"></a>
<span class="sourceLineNo">015</span><a name="line.15"></a>
<span class="sourceLineNo">016</span>/**<a name="line.16"></a>
<span class="sourceLineNo">017</span> * Comparator for version numbers.<a name="line.17"></a>
<span class="sourceLineNo">018</span> *<a name="line.18"></a>
<span class="sourceLineNo">019</span> * &lt;p&gt;<a name="line.19"></a>
<span class="sourceLineNo">020</span> * Version numbers are broken up into &lt;b&gt;parts&lt;/b&gt;, where a &lt;b&gt;part&lt;/b&gt; is a contiguous sequence<a name="line.20"></a>
<span class="sourceLineNo">021</span> * of one or more digits, or a contiguous sequence of one or more non-digits, and where the period character<a name="line.21"></a>
<span class="sourceLineNo">022</span> * ('.') serves as a part separator. Then, parts are compared pair-wise until there is a difference, as<a name="line.22"></a>
<span class="sourceLineNo">023</span> * determined by the {@link Comparator} provided to the constructor, or one version string runs out of parts,<a name="line.23"></a>
<span class="sourceLineNo">024</span> * in which case it is less than the other.<a name="line.24"></a>
<span class="sourceLineNo">025</span> * &lt;/p&gt;<a name="line.25"></a>
<span class="sourceLineNo">026</span> */<a name="line.26"></a>
<span class="sourceLineNo">027</span>public class VersionComparator implements Comparator&lt;String&gt; {<a name="line.27"></a>
<span class="sourceLineNo">028</span><a name="line.28"></a>
<span class="sourceLineNo">029</span>    private static final Pattern PART_PATTERN = Pattern.compile("[0-9]+|[^0-9.]+|\\.");<a name="line.29"></a>
<span class="sourceLineNo">030</span><a name="line.30"></a>
<span class="sourceLineNo">031</span>    private final Comparator&lt;String&gt; partComparator;<a name="line.31"></a>
<span class="sourceLineNo">032</span><a name="line.32"></a>
<span class="sourceLineNo">033</span>    /**<a name="line.33"></a>
<span class="sourceLineNo">034</span>     * Primary constructor.<a name="line.34"></a>
<span class="sourceLineNo">035</span>     *<a name="line.35"></a>
<span class="sourceLineNo">036</span>     * @param partComparator compares individual parts<a name="line.36"></a>
<span class="sourceLineNo">037</span>     * @throws IllegalArgumentException if {@code partComparator} is null<a name="line.37"></a>
<span class="sourceLineNo">038</span>     */<a name="line.38"></a>
<span class="sourceLineNo">039</span>    public VersionComparator(Comparator&lt;String&gt; partComparator) {<a name="line.39"></a>
<span class="sourceLineNo">040</span>        if (partComparator == null)<a name="line.40"></a>
<span class="sourceLineNo">041</span>            throw new IllegalArgumentException("null partComparator");<a name="line.41"></a>
<span class="sourceLineNo">042</span>        this.partComparator = partComparator;<a name="line.42"></a>
<span class="sourceLineNo">043</span>    }<a name="line.43"></a>
<span class="sourceLineNo">044</span><a name="line.44"></a>
<span class="sourceLineNo">045</span>    /**<a name="line.45"></a>
<span class="sourceLineNo">046</span>     * Convenience constructor.<a name="line.46"></a>
<span class="sourceLineNo">047</span>     *<a name="line.47"></a>
<span class="sourceLineNo">048</span>     * &lt;p&gt;<a name="line.48"></a>
<span class="sourceLineNo">049</span>     * Equivalent to &lt;code&gt;VersionComparator(new VersionPartComparator())&lt;/code&gt;.<a name="line.49"></a>
<span class="sourceLineNo">050</span>     */<a name="line.50"></a>
<span class="sourceLineNo">051</span>    public VersionComparator() {<a name="line.51"></a>
<span class="sourceLineNo">052</span>        this(new VersionPartComparator());<a name="line.52"></a>
<span class="sourceLineNo">053</span>    }<a name="line.53"></a>
<span class="sourceLineNo">054</span><a name="line.54"></a>
<span class="sourceLineNo">055</span>    @Override<a name="line.55"></a>
<span class="sourceLineNo">056</span>    public int compare(String v1, String v2) {<a name="line.56"></a>
<span class="sourceLineNo">057</span><a name="line.57"></a>
<span class="sourceLineNo">058</span>        // Chop up version into parts, where a part is a contiguous all-digit or all-non-digit sequence<a name="line.58"></a>
<span class="sourceLineNo">059</span>        List&lt;List&lt;String&gt;&gt; partsList = new ArrayList&lt;List&lt;String&gt;&gt;(2);<a name="line.59"></a>
<span class="sourceLineNo">060</span>        partsList.add(this.separateIntoParts(v1));<a name="line.60"></a>
<span class="sourceLineNo">061</span>        partsList.add(this.separateIntoParts(v2));<a name="line.61"></a>
<span class="sourceLineNo">062</span><a name="line.62"></a>
<span class="sourceLineNo">063</span>        // Compare parts pair-wise<a name="line.63"></a>
<span class="sourceLineNo">064</span>        for (int i = 0; true; i++) {<a name="line.64"></a>
<span class="sourceLineNo">065</span>            final boolean hasPart1 = i &lt; partsList.get(0).size();<a name="line.65"></a>
<span class="sourceLineNo">066</span>            final boolean hasPart2 = i &lt; partsList.get(1).size();<a name="line.66"></a>
<span class="sourceLineNo">067</span>            if (!hasPart1 &amp;&amp; !hasPart2)<a name="line.67"></a>
<span class="sourceLineNo">068</span>                return 0;<a name="line.68"></a>
<span class="sourceLineNo">069</span>            else if (hasPart1 &amp;&amp; !hasPart2)<a name="line.69"></a>
<span class="sourceLineNo">070</span>                return 1;<a name="line.70"></a>
<span class="sourceLineNo">071</span>            else if (!hasPart1 &amp;&amp; hasPart2)<a name="line.71"></a>
<span class="sourceLineNo">072</span>                return -1;<a name="line.72"></a>
<span class="sourceLineNo">073</span>            final String part1 = partsList.get(0).get(i);<a name="line.73"></a>
<span class="sourceLineNo">074</span>            final String part2 = partsList.get(1).get(i);<a name="line.74"></a>
<span class="sourceLineNo">075</span>            int diff = this.partComparator.compare(part1, part2);<a name="line.75"></a>
<span class="sourceLineNo">076</span>            if (diff != 0)<a name="line.76"></a>
<span class="sourceLineNo">077</span>                return diff;<a name="line.77"></a>
<span class="sourceLineNo">078</span>        }<a name="line.78"></a>
<span class="sourceLineNo">079</span>    }<a name="line.79"></a>
<span class="sourceLineNo">080</span><a name="line.80"></a>
<span class="sourceLineNo">081</span>    /**<a name="line.81"></a>
<span class="sourceLineNo">082</span>     * Split a version string into parts.<a name="line.82"></a>
<span class="sourceLineNo">083</span>     *<a name="line.83"></a>
<span class="sourceLineNo">084</span>     * &lt;p&gt;<a name="line.84"></a>
<span class="sourceLineNo">085</span>     * The implementation in {@link VersionComparator} defines a &lt;b&gt;part&lt;/b&gt; as a contiguous sequence<a name="line.85"></a>
<span class="sourceLineNo">086</span>     * of one or more digits, or a contiguous sequence of one or more non-digits, and where the period character<a name="line.86"></a>
<span class="sourceLineNo">087</span>     * ('.') serves as a part separator.<a name="line.87"></a>
<span class="sourceLineNo">088</span>     * &lt;/p&gt;<a name="line.88"></a>
<span class="sourceLineNo">089</span>     *<a name="line.89"></a>
<span class="sourceLineNo">090</span>     * &lt;p&gt;<a name="line.90"></a>
<span class="sourceLineNo">091</span>     * Subclasses may choose to override this method to define parts differently.<a name="line.91"></a>
<span class="sourceLineNo">092</span>     * &lt;/p&gt;<a name="line.92"></a>
<span class="sourceLineNo">093</span>     *<a name="line.93"></a>
<span class="sourceLineNo">094</span>     * @param version the original version string<a name="line.94"></a>
<span class="sourceLineNo">095</span>     * @return the parts of the version string<a name="line.95"></a>
<span class="sourceLineNo">096</span>     */<a name="line.96"></a>
<span class="sourceLineNo">097</span>    protected List&lt;String&gt; separateIntoParts(String version) {<a name="line.97"></a>
<span class="sourceLineNo">098</span>        final ArrayList&lt;String&gt; partsList = new ArrayList&lt;String&gt;();<a name="line.98"></a>
<span class="sourceLineNo">099</span>        int pos = 0;<a name="line.99"></a>
<span class="sourceLineNo">100</span>        for (Matcher matcher = PART_PATTERN.matcher(version); matcher.find(pos); pos = matcher.end()) {<a name="line.100"></a>
<span class="sourceLineNo">101</span>            final String part = matcher.group();<a name="line.101"></a>
<span class="sourceLineNo">102</span>            if (!part.equals("."))<a name="line.102"></a>
<span class="sourceLineNo">103</span>                partsList.add(part);<a name="line.103"></a>
<span class="sourceLineNo">104</span>            else if (matcher.end() == version.length() || version.charAt(matcher.end()) == '.')<a name="line.104"></a>
<span class="sourceLineNo">105</span>                partsList.add("");<a name="line.105"></a>
<span class="sourceLineNo">106</span>        }<a name="line.106"></a>
<span class="sourceLineNo">107</span>        return partsList;<a name="line.107"></a>
<span class="sourceLineNo">108</span>    }<a name="line.108"></a>
<span class="sourceLineNo">109</span>}<a name="line.109"></a>
<span class="sourceLineNo">110</span><a name="line.110"></a>




























































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